1. Field of the Invention
The present invention relates generally to semiconductor wafer processing. More specifically, the present invention relates to a chamber in which a high-pressure semiconductor wafer process can be performed.
2. Description of the Related Art
In the manufacture of semiconductor devices, a surface of a semiconductor wafer (“wafer” or “substrate”) must be processed in a wafer processing operation. For example, in a wafer cleaning process, the surface of the wafer is processed to remove chemical and particulate contamination. If the contamination is not removed, semiconductor devices on the wafer may perform poorly or become defective. Often, the wafer processing operations need to be performed under high-pressure conditions. Continuing with the wafer cleaning process example, some wafer cleaning processes involve exposing the wafer surface to a supercritical fluid. In such processes, a high-pressure must be provided within a wafer processing volume to maintain the supercritical state of the supercritical fluid. Therefore, a wafer processing module (i.e., chamber) is required to maintain the high-pressure necessary for the wafer processing operation.
Typically, a number of different wafer processing operations are performed by a number of different wafer processing modules. In some instances the different wafer processing modules are attached to a common wafer transfer module that serves to transfer the wafer from one wafer processing module to another. FIG. 1 is an illustration showing a number of wafer processing modules 107A–107D attached to a wafer transfer module 101, in accordance with the prior art. The wafer transfer module 101 is generally isolated from a clean room 103 by a load/lock module 105. The wafer can be transferred from the clean room 103 through a slit valve 111F into the load/lock module 105. From the load/lock module 105, the wafer can be transferred through a slit valve 111E into the wafer transfer module 101. A robotic wafer handling device 109 can be provided to transfer the wafer to one of the number of wafer processing modules 107A–107D. Each of the number of wafer processing modules 107A–107D can be isolated from the wafer transfer module 101 by one of a number of slit valves 111A–111D, respectively. Each of the slit valves 111A–111D must be capable of withstanding a pressure differential that exists between each of the wafer processing modules 107A–107D and the wafer transfer module 101. The wafer transfer module 101 is typically maintained at atmospheric or sub-atmospheric pressure. Therefore, if either of the wafer processing modules 107A–107D operate at a higher pressure, the pressure differential between the wafer processing module 107A–107D and the wafer transfer module 101 can become significant.
In view of the foregoing, there is a need for a high-pressure wafer processing module that can safely interface with a lower pressure wafer transfer module through a conventional slit valve. The high-pressure wafer processing module should be able to accommodate a high-pressure wafer process such as supercritical fluid cleaning.